Alternating current bells



Sept. 19, 1933. R. F. STEHLIK ALTERNATING CURRENT BELLS Filed 1929 2 Sheets-Sheet 1 Sept. 19, 1933. R STEHUK 1,927,530

ALTERNATING CURRENT BELLS Filed Oct. 9, 1929 2 Sheets-Sheet 2 Patented Sept. 19, 1933 UNITED STATES ALTERNATING oUnRENTBELLs V Rudolph Frank Stehlik,

Chicago, Ill., assignor to Associated Telephone and Telegraph Com pany, Chicago, 111., a

corporation of Delaware Application October 9, 1929, Serial No. 398,344, and in Great Britain October 28, 1928 4 Claims.

The present invention relates to alternating current. bells or the like and more particularly concerns bells suitable for use in telephone systems or similar situations. The principal object of the invention is to provide a bell which can be manufactured cheaply and in addition to being ,very light in weight, possesses great compactness 50 that it can be installed in a conveniently small space.

The usual construction of such bells has been with two coils wound on a U-shaped core polarized by a permanent magnet so as to cause the armature, mounted symmetrically with respect to the coils, to oscillate when the coils are traversed by alternating current. One feature of the present invention concerns the satisfactory-operation of the bell by the use of only a single energizing coil which is preferably provided with soft iron pole-pieces which are located opposite the ends of the armature.

A second feature of the invention relates to the mounting arrangements for the gongs. These are separately mounted on brackets and adjustably secured to the iron core of the energizing coil and are also arranged to be pivotally secured to the bracket so that they may be rotated to take up the most convenient position according to the size and shape of the space available in the type of instrument with which they are employed.

A description will now be given of one embodiment of the invention though it will be understood that this is given by way of example only and that the scope of the invention is not limited to the precise arrangement shown.

Referring now to the accompanying drawings, Fig. 1 shows a front elevation of the bell complete; Fig. 2 is a side elevation corresponding to Fig. 1; Figs. 3, 3a and 3b show different views of the mounting bracket, Fig. 31) being a section on the line AA of Fig. 3, while Fig. 4 shows one particular form of the coil head or pole piece.

Referring to'Fig. 1, the frame 11, constructed of brass or other suitable non-magnetic material, is

shown supporting the ringer coil 14, wound onaniron core-20, to which are adjustably secured the gong brackets 21 and 21 and gongs 25 and 25. Two flanges 12 and 12 on'the frame 11 form a bearing for the armature 30. The particular form of the mounting frame can be more clearly ascertained from Figs. 3, 3a and 3b. Flanges 32 form guides for the coil pole-pieces 33 holding the coil 14. Openings 34 are provided in the upper edges, having slots 35 (see Fig. 3b) through which screws 18 pass, to secure the pole-pieces 19, which are extended portions of the pole-pieces 33, to

the frame 11. It will be appreciated therefore that the coil :14 can readily be moved within the limits imposed by the length of the slots 35 and by means of this adjustment, the stroke of the armature can be adjusted. The flanges 12 and 12 are provided with holes 13 for receiving a bearing pin for supporting the armature 30. The armature is provided with centrally disposed flanges 36, which act as bearing plates, while one of these flanges is extended, as at 37 (see Fig. 2) for sup-. porting the rod 26 and hammer 38 which are secured to it by means of the bolt 27. The armature 30 is polarized by the permanent magnet so that there is a tendency for it normally to occupy one position, which tendency is assisted by' means of the biasing spring 31, so that the hammer is normally in engagement with the righthand gong The permanent magnet 15 is secured to the frame 11 by the bracket 16, which is itself secured by screws 17. t

The magnetic circuits over which the .flux flows when the coil 14 is energized, extends from the iron core 20, through the pole-pieces 33 on each end of the core 20, then through the extended portions 19 of the pole-pieces 33 and through the armature 30.

On the energization of the coil 14-. by current in the proper direction the armature is moved to its alternate position against the aciton of the spring 31, whereupon the hammer 38 is caused to strike the left-hand gong 25, while with current in the reverse direction the armature is returned to its initial position, whereupon the hammer strikes the right-hand gong 25. In this manner the alternate energization and de-energization of the coil 14 produces the required ring.

The gong mounting brackets 21 and 21 are rigidly secured to the iron core 20 by means of bolts 22. The particular construction of these brackets can be more clearly seen from Fig. 2; and it will be appreciated that each gong and gong bracket is secured independently of the other, to facilitate individual adjustment, or replacement if necessary. The gong 25 is rigidly secured to member 39 by means of screw 23. The member 39 is pivotally secured to the bracket 21 by means of the screw 24, and in this manner the member 39 and hence the gong 25 can be rotated about an axis which coincides substantially with the path of the hammer, so that the gongs 1 can take up a position which is most convenient with respect to the particular location of the bell. This feature is of particular advantage where space is'limited or where the bell is to be mounted in a space having a peculiar shape.

From the foregoing it will be appreciated that a new bell has been devised, which is very cheap to manufacture, is very compact, requiring very little space for mounting, and is comparatively light in weight.

What I claim as new and desire to secure by Letters Patent is:-

1. In an electric bell, a bar electromagnet having pole-pieces extending from the ends thereof, an armature; means, including a frame arranged parallel to said electromagnet and engaging the ends of said pole pieces, for pivotally supporting said armature between the ends of said polepieces; a pair of gongs and means supporting them from the ends of said electromagnet, and a clapper fastened to said armature and extending between said gongs.

2. In an electric bell, a straight bar-type electromagnet having pole pieces on the respective ends thereof, an armature for said electromagnet; means for pivotally supporting said armature, between said pole-pieces, comprising a supmagnet, a clapper fastened to said armature and extending between said gongs, and a permanent magnet fixed to said supporting frame at a point adjacent the mid-point of said armature, the permanent magnet extending at right angles to the axis of and partially surrounding said electromagnet.

3. In an electric bell, a straight electromagnet having a pair of pole-pieces projecting to the side of the ends thereof, means supporting a pair of gongs from the ends of said electromagnet on the side thereof opposite to the one at which said pole-pieces are located, a frame attached to the ends of said pole-pieces, an armature pivotally attached to said frame and arranged parallel to said electromagnet, a clapper attached to said armature and extending perpendicularly therefrom and perpendicular to the axis of said electromagnet to a position between said gongs, and a permanent magnet secured to said frame at a point adjacent the mid-point of said armature, the permanent magnet extending at right angles to the axis of and partially surrounding said electromagnet.

4. In an electric bell assembly, a gong, a memher on which said gong is supported, a second member on which said first member is pivotally supported, a striker for engaging the edge of said.

gong, the axial line of the pivot passing through the point of contact between said gong and striker so that said gong when turned about its pivot will remain in operative relation to said striker.

RUDOLPH FRANK STEHLIK. 

